Multiple-toothed circular saw with stabilizing holes



Feb. 2, 1954 GQMMEL 2,667,904

MULTIPLE-TOOTHED CIRCULAR SAW WITH STABILIZING HOLES F iled Nov. 20,1952 INVENTOR. :1 25 Wm,

M71 g ma' Patented Feb. 2, 1954 nutr rtarcorncn ciacurna .aw

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Dewey E". Gommel, Indianapolis, Ind, assignonto Borg-Warner Gorporation,Chicago, 111., a cor poration at Illinois arncannsmmter 2'0, lasa's nai32.1,.

6 Claims.

The present invention relates to circular saw blades, and particularlyconcerned with the problem of providing, in such blades, a system ofperforation units of such character as to stabilize such blades. Theinvention deals directly with the problem or providing for suchstabiliza-i tion of blades; which are so small and which have so manyteeth that it is impossible to ar range a single series of perforationsof adequate individual area, equal in number to. the teeth, in a singleconcentric series.

To the accomplishment of the abov and re. lated objects, myinvention maybe embodied in the forms illustrated in the accompanying drawr ings,attention being called to. the fact, however, that the drawings are.illustrative only, and that change may be made in the specificconstructions illustrated and described, so. long as. the scope of theappended. claims is. not violated.

Fig. 1 is a fragmentary elevation of a saw blade constructed inaccordance with the present. invention, certain dimension lines andhypothetie cal perforations appearing therein;

Fig. 2 is a similar view showing a modified form of my invention; and

Fig. 3 is a similar view showing a still further form of my invention.

In Fig. l, the reference numeral. It). indicates generally a circularsaw blade provided with a circular series of teeth it separated: byullets l2, said blade being centrally perforated r oth rwise formed (notshown): or mcuntins upon a suitable spindle, all in. accordance withGen-Yell:- tional. practice. In. the particular time of b ade selected fr lustration. the ac ualcuttine. elements are bits of u sten a bide.uitably securedto the blade. Saws, this character are re atively smallin. diameter and. are nrc ided with a; lar e num er o teeth ciada-seated per pheral arr n ment.

The p tent. o (Sharia. Na, hfiqag lh issued September 2. 1952. sh ws.her stabil a nof a ade can; he.- accomn ished by: the ne ment, near itsper hcry, o sin ,1IQ: I of p rf r tio s. ual. n but taseered. relation,to the teeth, of the blade. I have disco d t. in ord r oobtain optimum rsu ts. from e use. i such. an: ar angement, t e pe i ns u a e. n fectiteaareaatl as the q i t f 0-0 3. square tooth. and they must bearranged as close to the edge of the saW as is feasibl without producingundue weakening directly at the edge. The distance tw en. an. e e of; aper oration nd: the'closest point of any gullet, however., must. e atleast equal to the dimension of the perforation measured peripherally ofthe blade. Additionally, it is necessarythat the peripheral spacing:between adjacent edgesoi adjacent perforations shall; be at least equaltothe dimension of a perforation, measured peripherally of the saw, inorder to avoid undue weakening thereof.

New, in many conventionai carbide-tipped saws, the teeth are so closelyspaced that it" is not possible to arrange therein a singlecircularseries of circular perforations, equal in number to the teeth,in accordance with the above quirements. Thus, as shown in Fig. 1,-Ihave provided a; single circular series" of circular" per-r forations l4arranged as close to the blade edge as is feasible, theind-iv-idual;perforations being inch in diameter and their numberbeing equaltoone-half" the' number of teeth l t. At Me, I have indicated what; wouldhappen if I attempted to provide a number of such perforae tions equalto thenumber of teeth. Quite ob! v-iously, adjacent perforations, undersuch ci'r cumstances, would be so closetogether as tov-io late the aboverequirement and to weaken the blade unduly. I

As indicated above, it is essential: that. the dimension [5 be at leastequal to: the diameter of a perforation l4, and it is my present. beliefthat th dimension l5 should preferably: slightly ex? ceed; suchdiameter.It is alsoessential; order to maintain desiredblade strength, thatdimen! sion ['8 exceed dimension i5. It. is notieasible; I have found,to arrangev a second series: or per forations, as suggested at Mb,spaced radially inwardly from the series of" perforationslik, the holesof such second series correspondingto al ternate teeth I I. This is for"the reason that sucha series of openings, staggered thus: with respectto. the holes M will weaken the blade to an unacceptable extent unless:the dimension i6 is at least' equal to the dimension l8; and when theholes MD are: spaced inwardly trom the blade periphery by such. adistance (I6J1, the holes Mbare found to be substantiallyinefilccs tiveto perform the desiredi stabilizing function; because they: are.necessarily-i too. from the blade periphery;

According to. thepresentinvention, then; I propose toprovidethebladelwith-aserieslofpertos ration units, indicated. generally the:numeral i3, arranged a circular seriesconcentriawith the series ofteeth- H, thenumben'oi perforation units 13; being. equal: to. oneehalfzthe number of teeth H. Eachsuch unit symmetricalaon ops posite: sidesof-v a; radius: of the: blade; whic hs stantia-lly bisects-theanelezincludedabe we n :a ii' drawn to the deepest points on the boundaresgf the two adjacent. gullets. mend. one'sumtullit i so arranged with.respect: tn each; snccessiv pa r of teeth, so. thatthel'eris; oneperforation un t or each pair of: teeth the. save; in: oth r: wards.Onerhalf as. many perforation units. teeth Each: such unithasanefiectireiareaexceedina;th area of a circleharing; adlamcbcri-cquet qi one: half? the peripheral; distances measured 01.13.he. circle joining the centers 0& nerforations: ll]. be: tween radiidrawn. to; deepest; points: on: the boundaries; of. adiacent; eullcta.I;v ii feselttll b lieve an effective area of 0.126 square inch to be aessential that the peripheral distance between;

adjacent edges of adjacent perforation units shall I,

be greater than the distance from an edge of any perforation to thenearest gulleti' that is, the dimension [8 andthe dimension, [9

must exceed the dimension-l5. 1 In the preferred form of my invention,illustrated in Fig. 1, each perforation unit comprises a drilled,circular hole l4, whose diameter must' larger, and a second drilled hole11, whose diameter must be less than that .of the hole 14, but at leastinch'and preferably inch. The centers of the holes I4 .and I! of eachperforation unit are located on a common radius of the saw, which radiussubstantially bisects the angle included between radii drawn to thedeepest points on the boundaries of the gullets I2 just a-head.of,'andjust behind, the location of the perforation unit. The dimension [5exceeds the diameter of the hole I4, and the dimension [8 exceeds thedimension 15. The dimension 19 will be at least equal to, and preferablysomewhat greater than, the dimension 18. The dimension 20 may be justsufiicient toprevent the drill from breaking through from one hole intothe other during manufacture.

It will be seen that, if the hole l4 has a diameter of t; inch and thehole I! has a diameter of 4 inch, the effective area of the perforationunit will be 0.126 square inch.

In Fig. 2, I. have shown a modified form of my invention,,in which eachperforation unit 22 in a blade 2! comprises a slot, elongated in adirection radially of the blade. As shown, the radially outer end ofeach slotis formed on a radius equal to the radius of the hole [4, theradially inner end of each slot is formed on a radius equal to theradius of the hole I1, and the sides of the slot are tangent to thecurved ends thereof. The long axis of each slot is located on a radiusof the blade which substantially bisects the angle included betweenradii'drawn to the deepest points on theboundaries' of the gullets l2immediately ahead-of, and immediately behind, the location of the slot,and thereis one slot for each pair of teeth.. Thus, the peripheralspacing between adjacent slots closely conforms to the peripheralspacing between adjacent perforation means of Fig. 1, and the effectivearea of the perforation means of Fig. 2 somewhat exceeds thatof Fig. 1.The minimum distancev from each perforation means of Fig. 2 tothenearest gullet is substantially the same as that of Fig. 1.

. Functionally, the structure of Fig. 2 is believed closure, it ispossible to obtain, substantially to their maximum effectiveness, all ofthe advantages outlined in said Patent No. 2,609,017 in a saw whosediameter is so small, and the number of -whose teeth is so great, as toprevent the use thereinof the precise teaching of said patent;

andJI am presentlyofthe opinion that those advantages cannot beobtained, for such a saw, in

any other way. 5

I claimas my invention:

' 1. A circulahsaWperforated at its central be at least inch and ispreferably inch or E to be the full equivalent of that of Fig. 1, but of7 Fig. 3 shows an arrangement similar to that of Fig. 2 except that theinner and outerends of the slots 24 cut in the blade 23 are formed .upona com'monradius which, as shown, is equal to that of the holes 11. Thus,the effective area of each perforation unit of Fig. 3 is intermediatethose of Fig. 1 and of Fig. 2. Similarly, the cost of manufacture andthe functional excellence of the form ofFig; 3 lie'between thecorresponding characteristics of the forms of Figs. 1 and 2.

By-followingthe teachings of'the present disregion for mounting on aspindle, and provided with a peripheral series of teeth separated bygullets, said saw being further provided with perforation units arrangedin a circular series concentric with said series of teeth, the number ofperforation units being equal to one-half the number of said teeth, theeffective area of each perforation-unitbeing at least 0.126 square inch,the distance, peripherally of said saw, between adjacent edges ofadjacent perforation units everywhere exceeding the minimum distancefrom the edge of any perforation unit to the nearest gullet, and thedimension of each perforation unit, in a direction radially of said saw,exceeding the dimension thereof in a direction peripherally of said saw.I

2. The saw of claim 1 in which each perforation unit is symmetrical-onopposite sides of a radiusof said saw which substantially bisects theangle included between-Zradii drawn to the deepest points on the'boundaries of the two adjacent gullets. V

3. The saw of claim 2 in" which each perforation unit comprisestwoindependent circular perforations.

4. The saw of claim 2 in which each perforation unit comprises anon-circular'slot elongated radiallyof said saw.

5. The saw of claim 4 in which each slot diminishes in Width,peripherally of said saw,

.as it approaches the center of said saw.

tance between radii drawn tothe deepest points i on the boundaries ofadjacent gullets, measured along a chord joining the radially outermostboundariesof adjacent perforation units, the distance, peripherally'of'said saw, between adjacent edges of adjacent perforation unitseverywhere exceeding the minimum distance from the edge of anyperforationunit to the nearest gullet, and, the dimensionof eachperforation unit, in a direction radially of said saw, exceeding thedimension thereof in a direction peripherally of said saw.

' DEWEY E. GOMMEL.

Number Date Name, 213,439 Miller Mar. 18, 1879 2,563,559. Sneva- Aug.'7, '1951 2,609,017 Chapin Sept. 2, 1952

